Testing whether entanglement is a matter of information or non-local?

In summary, depending on one's interpretation of quantum mechanics, entanglement can be seen as either a matter of information or as a potential "spooky action at a distance." While there are entrenched belief systems based on either view, it is possible to test entanglement through experiments such as releasing two entangled electrons and measuring their spins at different points. However, this does not necessarily provide a clear answer about the nature of entanglement, as there are still debates about the role of non-locality and causality in quantum phenomena. Further research and experiments are needed to gain a better understanding of entanglement.
  • #1
QuestionMarks
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Depending on who one asks and their interpretation of QM, entanglement seems to be either:

a) No problem at all. It's just a matter of information. If you knew one entangled electron was spin up, then the other must have been spin down by inference of the prepared state of the system.
b) Potentially "spooky action at a distance." One electron might well be able to tell the other to "flip" its spin instantaneously. Something worth figuring out, but not something we like because that would be non-local.

And I've seen some pretty entrenched belief systems based on either way. But couldn't we test this? I would assume we have already?

If not, why not some similar scenario as follows...
We have a set of points, notated by the following letters, where the distance between each adjacent point is the same as those of any other two adjacent points:

A---B---C---D---E---F---G

At (D), two entangled electrons are released, electron 1 moving to (A) and electron 2 moving to (G). Both paths are the same in characteristics. At point (C) the spin of electron 1 is measured as "up," thereby we "know" that of 2 is "down" at (E). At point (B) (or even we could say immediately at the measurement on point C), electron 1 is hit and its spin changed from "up" to "down". As both particles reach their endpoints, electron 2 is measured at (G).

If electron 2 is shown as "up," then would we not know that electron 1 somehow told electron 2 to flip sometime after (C-E)? Would this not support then that entanglement is not merely inference of information from the system, but rather an actual effect of one particle upon the other (even if it is non-local)? Surely something like this experiment has already been done?

thanks all.
 
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  • #2
QuestionMarks said:
If not, why not some similar scenario as follows...
We have a set of points, notated by the following letters, where the distance between each adjacent point is the same as those of any other two adjacent points:

A---B---C---D---E---F---G

At (D), two entangled electrons are released, electron 1 moving to (A) and electron 2 moving to (G). Both paths are the same in characteristics. At point (C) the spin of electron 1 is measured as "up," thereby we "know" that of 2 is "down" at (E). At point (B) (or even we could say immediately at the measurement on point C), electron 1 is hit and its spin changed from "up" to "down". As both particles reach their endpoints, electron 2 is measured at (G).

If electron 2 is shown as "up," then would we not know that electron 1 somehow told electron 2 to flip sometime after (C-E)? Would this not support then that entanglement is not merely inference of information from the system, but rather an actual effect of one particle upon the other (even if it is non-local)? Surely this experiment has already been done?

thanks all.

Once electron 1 is observed to be spin up at (C), it is no longer entangled with electron 2. So what happens next to 1 has no effect on 2. You can be sure that once electron 2 is down, it will stay down (until some interaction or observation places it into a different state)! That is fairly fundamental.

So the expected null result in this case does not place us any closer to answering your question.
 
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  • #3
By the way, your question does not follow the norms of how entanglement is usually explained. The "information only" view is generally discredited if you are rejecting non-locality. You usually either reject "realism" or reject "locality" (or both). This is because of Bell's Theorem. :smile:
 
  • #4
Thanks DrChinese. Hah, good to know when one's brain feels it is missing something obvious, it nearly always is. So my proposition is bunk, but is there any experimental evidence that leans us closer to either understanding? Any key papers?

And I get Bell's theorem's sentiments, though I guess I should acknowledge that I'm not necessarily rejecting non-locality. I grant that's traditional, but I'm willing to consider alternatives. Perhaps consider me biased towards realism to keep the dialogue interesting.
 
  • #5
QuestionMarks said:
Thanks DrChinese. Hah, good to know when one's brain feels it is missing something obvious, it nearly always is. So my proposition is bunk, but is there any experimental evidence that leans us closer to either understanding? Any key papers?

And I get Bell's theorem's sentiments, though I guess I should acknowledge that I'm not necessarily rejecting non-locality. I grant that's traditional, but I'm willing to consider alternatives. Perhaps consider me biased towards realism to keep the dialogue interesting.

The state of the art has not proven or disproven direct non-local action. There is plenty of proof for quantum non-locality but there are some interpretations in which the action is not direct (example: time symmetric versions which respect c but do not respect causality as we know it).

It is possible to entangle particles that have never interacted, for example. Such particles need not have ever existed in the other's past time cone. Also: tests for non-locality have indicated that if non-local effects have a finite limit on the speed of action, it must be at least 10,000 c.
 
  • #6
DrChinese said:
The state of the art has not proven or disproven direct non-local action. There is plenty of proof for quantum non-locality but there are some interpretations in which the action is not direct (example: time symmetric versions which respect c but do not respect causality as we know it).

It is possible to entangle particles that have never interacted, for example. Such particles need not have ever existed in the other's past time cone. Also: tests for non-locality have indicated that if non-local effects have a finite limit on the speed of action, it must be at least 10,000 c.

All interesing ideas. Can any particular experiment names or search terms be put to these so I can do more reading?

Particularly though, how can you have a nonlocal effect that is indirect or still respects c as you say? And is "nonlocal" still an apt word for this? My thought would be that any event occurring to one particle and causally-correlating with an event on/to another could be described as information transfer. I've certainly read a handful of experiments where QM causality gets a little wonky, but I never felt any such adbicated those instances of our responsibility in considering nonlocal mechanisms.
 
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  • #7
QuestionMarks said:
1. All interesing ideas. Can any particular experiment names or search terms be put to these so I can do more reading?

2. Particularly though, how can you have a nonlocal effect that is indirect or still respects c as you say? And is "nonlocal" still an apt word for this? My thought would be that any event occurring to one particle and causally-correlating with an event on/to another could be described as information transfer. I've certainly read a handful of experiments where QM causality gets a little wonky, but I never felt any such adbicated those instances of our responsibility in considering nonlocal mechanisms.

1. Here are a few:

http://arxiv.org/abs/quant-ph/0201134
Decision to entangle 2 particles is made AFTER the particles have already been detected. Effect precedes the cause.

http://arxiv.org/abs/1209.4191
Entanglement Between Photons that have Never Coexisted; The observed quantum correlations manifest the non-locality of quantum mechanics in spacetime.

http://arxiv.org/abs/0808.3316
Testing spooky action at a distance; ...if such a privileged reference frame exists and is such that the Earth's speed in this frame is less than 10^-3 that of the speed of light, then the speed of this spooky influence would have to exceed that of light by at least 4 orders of magnitude.


2. An indirect non-local effect is one in which the causal arrow move back and forth, but otherwise respects c. The space-time diagram of the experimental context does not have anything propagating at a speed other than c or -c. You don't have to agree anything is proven to be time-reversed, but that is also an acceptable interpretation.
 
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  • #8
DrChinese said:
Once electron 1 is observed to be spin up at (C), it is no longer entangled with electron 2. So what happens next to 1 has no effect on 2. You can be sure that once electron 2 is down, it will stay down (until some interaction or observation places it into a different state)! That is fairly fundamental.

So the expected null result in this case does not place us any closer to answering your question.

In the context of spin 1/2 particles in a basic Bell inequality : n[x+,z+] + n[y-,z-] ≥ n[x+,y+]
Realism assumes that variables "Determine precisely the results of individual measurements". That is, if electron 1 is spin up on z axis then if electron 2 were measured it would be spin down on z axis , from conservation laws.
While once electron 1 is observed to be up it is no longer entangled with electron 2 and electron 2 will stay down.
Then when the above inequality is violated does this suggest there can be non-local influences between electrons that are not entangled ?
 
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  • #9
morrobay said:
In the context of spin 1/2 particles in a basic Bell inequality : n[x+,z+] + n[y-,z-] ≥ n[x+,y+]
Realism assumes that variables "Determine precisely the results of individual measurements". That is, if electron 1 is spin up on z axis then if electron 2 were measured it would be spin down on z axis , from conservation laws.
While once electron 1 is observed to be up it is no longer entangled with electron 2 and electron 2 will stay down.
Then when the above inequality is violated does this suggest there can be non-local influences between electrons that are not entangled ?

The inequality is not going to be violated if the x, y and z are all mutually orthogonal axes for measurement.

I would say: There is no suggestion that there is a non-local influence between electrons that are not entangled.
 
  • #10
This is all great reading resources DrChinese. Super thanks! I'll dig into these.

On the backwards c, I'm glad you mentioned that. That was actually an interpretation (in my own mind)of some results I read a while back, but when I looked around to see if this was a valid idea, it was very poo-pooed upon. Granted I understand one's interpretation of QM may create strong arguments to the contrary. Makes me wish, however, most QM conversations could be held in reference to the knowledge that a general interpretation is not yet consensus.

Anyways Thanks!
 
  • #11
DrChinese said:
It is possible to entangle particles that have never interacted, for example. Such particles need not have ever existed in the other's past time cone.

Just kind of an aside here...but how can you say with absolute certainty that two particles have never interacted? If we go all the way back to the beginning of this universe, all particles would have interaction with each other because they all would have been in the same space.
 
  • #12
QuestionMarks said:
Depending on who one asks and their interpretation of QM, entanglement seems to be either:

Actually its not dependant at all on interpretation. Its simply the vector space nature of pure states.

If you have two systems that can be in states |a> and |b> then system 1 can be in state |a> and system 2 in state |b> - their combined state is the pure state |a>|b>. Similarly system 1 can be in state |b> and system 2 in state |a>. Again their combined state is |b>|a>. But pure states form a vector space (that's the basis of the superposition principle) so a linear combination is also an allowable state eg 1/root 2 |a>|b> + 1/root 2 |b>|a>. By definition such states are called entangled.

In fact it is now known that a few reasonable assumptions and entanglement more or less implies QM:
http://arxiv.org/abs/0911.0695

The situation is this. The three axioms mentioned in the paper lead to either probability theory or quantum mechanics. Quantum mechanics is singled out if you want continuous transformations between pure states (physical continuity requires this ie if you can apply a transformation for 1 second you can apply it for 1/2 second) OR you can allow entanglement. At a deep fundamental level entanglement seems to be built into the very foundations of modelling physical systems.

Thanks
Bill
 
  • #13
trendal said:
Just kind of an aside here...but how can you say with absolute certainty that two particles have never interacted? If we go all the way back to the beginning of this universe, all particles would have interaction with each other because they all would have been in the same space.

You cant.

But what you can say is when you observe one part of an entangled system it's now entangled with what you observed it with rather then what it was originally entangled with.

Thanks
Bill
 
  • #14
DrChinese said:
The inequality is not going to be violated if the x, y and z are all mutually orthogonal axes for measurement.
It my understanding that QM predicts that two particles will be spin up or spin down: 1/2(sin(Θ/2))2


x y z...x y z
- - -...+ + +
- - +...+ + -
- + +...+ - -
+ + +...- - -
+ + -...- + +
+ - -...- + +
- + -...+ - +
+ - +...- + -

So if expectation values for the inequality are from table above and as shown spins in the
inequality are opposites then can it be violated at 900
n[x+,z-] + n[y-z+] ≥ n[x-,y+]
 
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  • #15
bhobba said:
Actually its not dependant at all on interpretation. Its simply the vector space nature of pure states.

...

Thanks
Bill

I'll check out that paper eventually, but I feel I'm likely to still disagree. Wherein we still currently have no fundamental consensus regarding the basic reality QM implies, I would find it overwhelmingly difficult to believe that entanglement enacts the same roles in all interpretations. Sure it can be given the same mathematical formulations, if you mean just that, but the reality (if there is one) is different. For instance, the MWI can have some sentiment of different entangled systems as different universes/histories. Meanwhile, Bohm's interpretation could quite literally count as spooky action if your requirement for that is simply a nonlocal hidden variable. QM may not depend on interpretation for the Math to be functional, but the ontology does.
 
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  • #16
Has any entanglement experiment proven that this following analogy is not akin to what is going on in the experiments (that is to say, has any entangle experiment proven non locality, in which this following analogy cannot be used to describe the most likely potential of what occurred)?There is a red ball and a blue ball. You and I are in another room blindfolded. A random person walks in the room with the red ball and blue ball and puts each in a bag. You and I walk in the room and each grab a bag. I go to the moon. You stay there. We know without looking that the results will be 1 red ball and 1 blue ball. I look in my bag on the moon, and its the blue ball. I instantly know that your ball is the red ball.

If this analogy can be used to describe every entanglement experiment, the analogy would be related to the 'spooky entanglement interpretation'; I got my bag and you get your bag. I go to the moon. Before I or your look in our bags, I have a red/blue ball in my bag, and you have a red/blue ball in your bag. When the bags were in the same room before they were separated, they were entangled. When I looked in my bag the red/blue ball turned into a blue ball, which then faster than the speed of light, notified your red/blue ball to turn into a red ball.

I honestly don't know much about this subject, but I like to remain skeptical, in the sense of believing in locality, cause and effect, logic, and the ability to explain physical interactions.
 
  • #17
Imafungi said:
Has any entanglement experiment proven that this following analogy is not akin to what is going on in the experiments (that is to say, has any entangle experiment proven non locality, in which this following analogy cannot be used to describe the most likely potential of what occurred)?
...

Yes. Google for "Bell's Theorem" and also check out http://www.drchinese.com/Bells_Theorem.htm - DrChinese is a regular contributor here.
 
  • #18
Nugatory said:
Yes. Google for "Bell's Theorem" and also check out http://www.drchinese.com/Bells_Theorem.htm - DrChinese is a regular contributor here.

Im sorry but I don't think that in anyway proved my analogy wrong, which is a 'local realism' view of the spooky action entanglement interpretation.

In entanglement experiments. When the first particle is measured, and the second particle is not measured. When the first particle is measured, at that instant does the second particle alert a system of its state? Or do the experimenters have to measure the second particle by themselves after? Or is it in a superposition in some apparatus either just vibrating in place or traveling around in a circle, and then the first particle is measured, and that second particle just instantly finds the nearest detector to exclaim to the experimenters that its entangled pair had been measured?
 
  • #19
Imafungi said:
Has any entanglement experiment proven that this following analogy . . . interactions.

You don't just open , you paint the ball , and statistic you get anather color far and fast
 
  • #20
QuestionMarks said:
I'll check out that paper eventually, but I feel I'm likely to still disagree. Wherein we still currently have no fundamental consensus regarding the basic reality QM implies

Well since there is no consensus on what reality even means that's hardly surprising.

In physics generally the math is assumed to describe reality without getting bogged down in exactly what it is in the first place. If you want to go beyond that you are really getting into philosophy rather than science.

QuestionMarks said:
QM may not depend on interpretation for the Math to be functional, but the ontology does.

Why do you need an ontology beyond a simple interpretation of probability, which you need to make sense of probability to begin with? If you adopt the frequentest view of probability you get the so called statistical interpretation championed by Ballentine. If you adopt a Baysian view then you get something like Copenhagen. Strictly speaking its an ontology, but you would have a lot of trouble convincing those with a background in applied math like me its really more than the formalism implies.

Thanks
Bill
 
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  • #21
bhobba said:
...
In physics generally the math is assumed to describe reality without getting bogged down in exactly what it is in the first place. If you want to go beyond that you are really getting into philosophy rather than science.

Why do you need an ontology beyond a simple interpretation of probability, which you need to make sense of probability to begin with?
...

That hints of the "shut up and calculate" culture often found in modern physics, which is a bit of a presumed philosophy itself unfortunately. And though we do not need the ontology per say, why discourage the pursuit? It only becomes philosophy (which is no evil, just a different forum) when we stop looking for empirical evidence. Presuming no experiment can be performed which would give us a better interpretational view of reality would be an unnecessary assumption (and I allow myself optimism at least). So until then, and especially while we are particularly focusing on what empirical support is out there, I see no concern in my thought venture.
 
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  • #22
morrobay said:
It my understanding that QM predicts that two particles will be spin up or spin down: 1/2(sin(Θ/2))2


x y z...x y z
- - -...+ + +
- - +...+ + -
- + +...+ - -
+ + +...- - -
+ + -...- + +
+ - -...- + +
- + -...+ - +
+ - +...- + -

So if expectation values for the inequality are from table above and as shown spins in the
inequality are opposites then can it be violated at 900
n[x+,z-] + n[y-z+] ≥ n[x-,y+]

The inequality is not violated at 90 degrees, because:

QM_Prediction(n[x+,z-])=25%
QM_Prediction(n[y-,z+])=25%
QM_Prediction(n[x-,y+])=25%

So that:

25% + 25% >= 25%

By the way, according to QM, the x, y and z spin components of an electron do not commute. A measurement of x requires that both y and z are completely indeterminate (and vice versa). So any x outcome (which will have a 50-50 likelihood) will be accompanied by a random outcome of either y or z. 50% x 50% = 25%.
 
  • #23
Imafungi said:
Im sorry but I don't think that in anyway proved my analogy wrong, which is a 'local realism' view of the spooky action entanglement interpretation.

In entanglement experiments. When the first particle is measured, and the second particle is not measured. When the first particle is measured, at that instant does the second particle alert a system of its state? Or do the experimenters have to measure the second particle by themselves after? Or is it in a superposition in some apparatus either just vibrating in place or traveling around in a circle, and then the first particle is measured, and that second particle just instantly finds the nearest detector to exclaim to the experimenters that its entangled pair had been measured?

First, no one actually understands the underlying mechanism by which entanglement works. That is why there are multiple interpretations. From 1935 until Bell's Theorem, your local realistic explanation was considered one possible interpretation (the EPR interpretation for lack of a better name).

However, Bell showed that interpretation to be flawed. The EPR interpretation has since been proven incorrect many times over in experiment. Until you read and understand Bell, you won't make any progress towards understanding WHY the EPR interpretation is wrong. Better yet, read the EPR paper first and then Bell.

BTW: In QM, the ordering of the measurements on Alice and Bob (particles 1 and 2) do not affect the outcome in any discernible fashion.
 
  • #24
QuestionMarks said:
So until then, and especially while we are particularly focusing on what empirical support is out there, I see no concern in my thought venture.

Well, it is incorrect as I explained. That should give you pause. You cannot maintain all of the elements you have proposed (causality and locality).

It is very common to speculate. That is the lifeblood of new ideas, most of which are completely wrong. It is not common to give credit to speculation for which there is no practical implication because there is no new useful prediction to test.

So the reason people exclude local realistic interpretations/theories is that they run afoul of Bell.
 
  • #25
QuestionMarks said:
That hints of the "shut up and calculate" culture often found in modern physics, which is a bit of a presumed philosophy itself unfortunately.

Or maybe you misinterpret taking the math at face value.

Its what led to perhaps the greatest revelation of modern physics:
http://arxiv.org/pdf/hep-th/9704139.pdf

'The most important lesson that we have learned in this century it is that the secret of nature is symmetry. Starting with relativity, proceeding through the development of quantum mechanics and culminating, in the standard model symmetry principles have assumed a central position in the fundamental theories of nature. Local gauge symmetries provide the basis of the standard model and of Einstein’s theory of gravitation.'

It was the math of QM that revealed this - ontological speculations have basically led no-where.

Thanks
Bill
 
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  • #26
DrChinese said:
First, no one actually understands the underlying mechanism by which entanglement works. That is why there are multiple interpretations. From 1935 until Bell's Theorem, your local realistic explanation was considered one possible interpretation (the EPR interpretation for lack of a better name).

However, Bell showed that interpretation to be flawed. The EPR interpretation has since been proven incorrect many times over in experiment. Until you read and understand Bell, you won't make any progress towards understanding WHY the EPR interpretation is wrong. Better yet, read the EPR paper first and then Bell.

BTW: In QM, the ordering of the measurements on Alice and Bob (particles 1 and 2) do not affect the outcome in any discernible fashion.


Someone posted me information regarding Bells theorem, it didnt appear to contradict what I was saying. It doesn't seem itself to be based on evidence or experiment either, it appears to be a philosophical exclamation based entirely on assumptions made of what a local realist assumes. I saw the 1. 2. 3. argument part, and it says like, for the local realist to be right they need to believe all 3, but according to a non local realists interpretation of entanglement some of the tenants cannot be correct, therefore the local realist is wrong if they try to believe all the tenants?

Can you please answer this question, it is very important for my understanding of the true nature of all entanglement experiments, and an answer that suggests a; Yes, in regards to the first and third questions (which are the same question, worded differently and for clarity) would make me greatly comprehend that my analogy and interpretation lacking, and I would become forced to consider true non locality entanglement reality:

In entanglement experiments. When the first particle is measured, and the second particle is not measured. When the first particle is measured, at that instant does the second particle alert a system of its state? Or do the experimenters have to measure the second particle by themselves after? Or is it in a superposition in some apparatus either just vibrating in place or traveling around in a circle, and then the first particle is measured, and that second particle just instantly finds the nearest detector to exclaim to the experimenters that its entangled pair had been measured?
 
  • #27
DrChinese said:
Well, it is incorrect as I explained. That should give you pause. You cannot maintain all of the elements you have proposed (causality and locality).

It is very common to speculate. That is the lifeblood of new ideas, most of which are completely wrong. It is not common to give credit to speculation for which there is no practical implication because there is no new useful prediction to test.

So the reason people exclude local realistic interpretations/theories is that they run afoul of Bell.

What is incorrect? What should give me pause?
The initial experimental proposition is incorrect, certainly. Should I pause on questioning what experiments have been done? Where am I speculating beyond to ask what current experiments have addressed the question I posed? And where am I asserting something against Bell's? At most I have mentioned a non-local, hidden-variable theorem interpretation like Bohm's is possible (which takes no issue with Bell), and therefore we shouldn't say these questions matter nothing. This was only an aside in response to another poster, as I felt my questions have been quite well addressed by you (thanks by the way).
 
  • #28
QuestionMarks said:
What is incorrect? What should give me pause?
The initial experimental proposition is incorrect, certainly. Should I pause on questioning what experiments have been done? Where am I speculating beyond to ask what current experiments have addressed the question I posed? And where am I asserting something against Bell's? At most I have mentioned a non-local, hidden-variable theorem interpretation like Bohm's is possible (which takes no issue with Bell), and this was only an aside in response to another poster.

My mistake, I thought you had gone back to a local "information only" interpretation. :smile:
 
  • #29
bhobba said:
It was the math of QM that revealed this - ontological speculations have basically led no-where.

Why should this limit my curiosity though? And why should we presume (as is the connotation I'm hearing) no math will ever help sway us to one ontology or another? Particularly, should I refrain from questioning if there is any experimental existing evidence towards these considerations (as this is what I have done)?

Again, I don't see the problem here. It seems like we are straining gnats. My question has been answered sufficiently already, and I am attempting to promote nothing more.
 
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  • #30
DrChinese said:
My mistake, I thought you had gone back to a local "information only" interpretation. :smile:

Oh no, though I guess I should have qualified that I never meant that necessarily local anyways. Re-reading my original post, I see the quandary. But I didn't want to assert any particular view or engage in speculation off it. I just wanted to know what experiments were possible/had existed, and I think I've got sufficient reading to do there. If anybody ends up waning to close this to prevent it from meandering off-topic needlessly, I feel sated.
 
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  • #31
trendal said:
Just kind of an aside here...but how can you say with absolute certainty that two particles have never interacted?

How? Because the photons did not exist at the same time, in any reference frame.

Now, you can always argue that the photons did not exist at the same point in time, but the apparati that gave rise to them did. True enough, and therein lies part of the problem. They can be created by separate lasers that have interacted in the past. (In fact, the lasers will need to be phase locked to each other to create the effect.)

However, that doesn't change the fundamental issue that they can be entangled after neither exist any longer. And that a future setup is an integral part of the overall context (don't forget Bell). So arguing that there are hidden variables in place at the creation of the photon pair that are identical for both becomes untenable. Keep in mind that every photon emerging from any laser is essentially phase locked to every other one - and yet they are NOT all entangled. So then you must ask how the pairs that display entanglement got that way. And it is not because they interacted in the past.
 
  • #32
QuestionMarks said:
That hints of the "shut up and calculate" culture often found in modern physics, which is a bit of a presumed philosophy itself unfortunately. And though we do not need the ontology per say, why discourage the pursuit? It only becomes philosophy (which is no evil, just a different forum) when we stop looking for empirical evidence. Presuming no experiment can be performed which would give us a better interpretational view of reality would be an unnecessary assumption (and I allow myself optimism at least). So until then, and especially while we are particularly focusing on what empirical support is out there, I see no concern in my thought venture.

The "shut up and calculate" attitude is a little bit unfortunate, because in the past, thinking about ontology---what might be REALLY going on that would explain the mathematics---is often a good way to get ideas for new (testable) theories that go beyond existing theories. A sort-of example was that once upon a time, there was a very sophisticated mathematical theory that was used to calculate celestial quantities such as timing of eclipses, and positions of planets, etc. This was the Ptolemy theory, which basically described the motion as planets moving on the surface of spheres, which move on larger spheres, which move on larger spheres, etc. The innermost sphere was centered on the Earth. Then Kepler saw that if you instead allow planets to move in ellipses, and shift the center from the Earth to the Sun, the same predictions could be made much simpler. And Kepler's theory itself inspired Newton's law of gravity.

In the case of quantum mechanics, it's certainly possible that thinking about ontology will lead to something new and interesting. However, every attempt along those lines has resulted in making things more complicated without making any improvements to the ability to make predictions. So except for a small number of noncomformists, I think most people have given up on ontology. That's what "shut up and calculate" means to me.
 
  • #33
QuestionMarks said:
Why should this limit my curiosity though?

Of course it shouldn't.

You can go in any direction you feel like - and indeed that is one of the hallmarks of science - as one whit said - free scientific enquiry - the first word is redundant. :-p:-p:-p:-p

I am simply pointing out interpretive type speculations that are not experimentally testable haven't led anywhere - and indeed if they are not experimentally testable many would argue it is unlikely to. But opinions are like bums - everyone has one - it doesn't make it correct - even mine - no - especially mine.

In this connection though I must point out forum rules don't allow philosophy. Discussing and understanding what various interpretations say is on topic, but philosophically dissecting them isn't.

Thanks
Bill
 
  • #34
bhobba said:
In this connection though I must point out forum rules don't allow philosophy. Discussing and understanding what various interpretations say is on topic, but philosophically dissecting them isn't.l

Exactly. But I am not the one doing this. My question was asking about empirical evidence that might or might not be accessible regarding a matter, and that's done.
 
  • #35
bhobba said:
Of course it shouldn't.

You can go in any direction you feel like - and indeed that is one of the hallmarks of science - as one whit said - free scientific enquiry - the first word is redundant. :-p:-p:-p:-p

I am simply pointing out interpretive type speculations that are not experimentally testable haven't led anywhere - and indeed if they are not experimentally testable many would argue it is unlikely to. But opinions are like bums - everyone has one - it doesn't make it correct - even mine - no - especially mine.

In this connection though I must point out forum rules don't allow philosophy. Discussing and understanding what various interpretations say is on topic, but philosophically dissecting them isn't.

Thanks
Bill

Science cannot exist without philosophy when considering generally 'philosophy' is 'to think'.
 

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